In general, a hinge of this type comprises a skeleton side attaching member fixed to the skeleton, a door side attaching member fixed to the door, an inner and an outer link for turnably connecting the door side attaching member to the skeleton side attaching member between a closed position and an open position, and a coiled spring for turnably biasing the door side attaching member through selected one of the inner and outer links. When the door is located in a position offset to the closed position side from a predetermined neutral position between the closed position and the open position, the coiled spring rotationally biases the door side attaching member towards the closed position side from the open position side. And when the door is located in a position offset to the open position side from the neutral position, the coiled spring rotationally biases the door side attaching member to the open position side from the closed position side.
One end of the coiled spring is abutted with the selected link in order to bias the link. Accordingly, the contact place of the selected link with respect to the coiled spring is rubbed by one end of the coiled spring when the link is turned in accordance with the turning motion of the door side attaching member. As a result, this link is liable to be worn quickly. In order to overcome this inconvenience, Japanese Utility Model Application Laid-Open Publication No. S61-197178 discloses a hinge including a pair of links, an abutment shaft turnably disposed at one of the links and a coiled spring one end of which is abutted with the abutment shaft. Owing to this arrangement, since the abutment shaft is in rolling contact with one end of the coiled spring, the abutment shaft can be prevented from wearing quickly.
The hinge which is described in the above Publication, however, has such a problem that much elaboration is required for mounting the abutment shaft on the selected link. That is, in the hinge described in the above Publication, in order to turnably mount the abutment shaft on the selected link a support hole is formed in each side of the selected link and the opposite ends of the abutment shaft are inserted in the respective support holes. With this arrangement, although the abutment shaft can be inserted in a selected one of the support holes comparatively easily, it is comparatively difficult to insert the abutment shaft, which is already inserted in the selected support hole, in the other support hole because the length of the abutment shaft is much greater than the outside diameter of the abutment shaft. For this reason, much elaboration is required to mount the abutment shaft on the selected link.